• Development and Reproduction
• /
• v.18 no.1
• /
• pp.51-56
• /
• 2014

This study describes the developmental process of gonads in chameleon goby, Tridentiger trigonocephalus from the stage of hatching to 100 days after hatching (DAH). Based on histological observation, the primordial germ cells were observed in mesentery between mesonephric duct and gut at 15 DAH (total length, TL: $6.8{\pm}0.2mm$). At 20 DAH (TL: $7.9{\pm}0.1mm$), the primordial gonad began to protrude into peritoneal cavity and developed between mesonephric duct and gut. Initial ovarian differentiation was identified by the presence of ovarian cavity and oogonia in the gonads at 55 DAH (TL: $21.1{\pm}1.3mm$). Testicular differentiation started at 65 DAH (TL: $23.7{\pm}0.9mm$) with appearance of spermatogonial cells in the gonads. These findings indicate that sex differentiation in T. trigonocephalus occurs earlier in females than males, suggesting that this species can be classified as an undifferentiated gonochorist.

• Development and Reproduction
• /
• v.24 no.3
• /
• pp.225-230
• /
• 2020

This study reports the presence of mature and bi-sexual phase gonads in red spotted grouper, Epinephelus akaara after less than a year of cultivation in a commercial indoor tank and a net cage. In December 2018, juveniles were placed in an indoor tank and cultured for five months. In June 2019, the fish were transferred to a net cage and cultured until September. The rearing temperatures ranged from 19.86℃-24.65℃ in the indoor tank and 21.86℃-27.65℃ in the net cage. During the net cage culture period, specimens were randomly selected for histological gonad examination. The highest gonadosomatic index (GSI) value was measured in July (3.38±2.53), and dramatically decreased in August (0.44±0.21) and September (0.42±0.30). In July, some mature fish showed signs of vitellogenic stage oocyte development (vitellogenic and oil droplet stage oocytes), but immature fish were in an early developmental stage containing peri-nucleolus stage (PNS) oocytes. Bi-sexual phase gonads containing spermatocytes and spermatids were observed in the lumen and several PNS oocytes. By August and September, most specimens showed early-stage ovary development. However, mature testis (in August) and bi-sexual phase gonads (in September) were also observed. These results provide evidence for early puberty and hermaphroditism in the red spotted grouper.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.57 no.2
• /
• pp.145-152
• /
• 2024

The present study investigated the digital color characteristics corresponding to different maturity stages and maturation levels of white croaker Pennahia argentatus specimens collected from the Southern Sea of South Korea. Maturity stages were determined using photomicrographs depicting ovarian developmental phases and compared with digital color values. The specimens ranged in body length from 21-36 cm, with mature ovaries observed within the 24-30 cm length range. To differentiate the maturing, mature, spawning, and post-spawning stages of the gonads, boundary lines were established based on specific coordinates. For the ovaries, a dividing line was drawn through (-10, -10) and (15, 5), described by the equation Y=3/5X-4; while for the testes, the line passed through (20, 0) and (0, 15), indicated by the equation Y=-3/4X+15. However, the visual determination of the maturity stages proved challenging due to overlapping color values. Consequently, this study underscores the efficacy of employing digital color measurements over subjective visual assessments to evaluate the maturity of white croaker gonads and offers more quantitative insights.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.20 no.6
• /
• pp.489-500
• /
• 1987

Annual reproductive cycle of Bluegill, Lepomis macrochirus (RAFINESQUE) were studied in the natural population. Based on these informations, reproductive mechanism of the fish including activation, degeneration and remature were examined under the controlled conditions of temperature and photoperioe. In the natural populations, gonads began to grow with the temperature increase in March ana matured in June, and spawning occurred in July. With the onset of the shorter day-length and the maximum temperature condition in August, the gonads began to degenerate. Resting stage was continued during winter season. In the laboratory-reared population, activation of the gonads was initiated by the complex environmental factors including higher temperature$(>15^{\circ}C)$ and longer photoperiod $(>14L)$. For the maturation, photoperiod of more than 14 hours was critical. Under this condition higher temperature was the only compensative factor. Regeneration of the gonads was induced by higher temperature$(>25^{\circ}C)$ and the shorter photoperiod accelerated the regenerative processes. Even from the resting stage the gonads can be induced to matured stage by the longer photoperiod $(>15L)$. Based on these observations, the reproductive rhythm of this fish is supposed to be artificially controlled.

• The Zoological Society Korea : Newsletter
• /
• v.12 no.2
• /
• pp.104.2-104
• /
• 1995

• Proceedings of the Zoological Society Korea Conference
• /
• 1995.10b
• /
• pp.232.2-232
• /
• 1995

• Proceedings of the Zoological Society Korea Conference
• /
• 1996.10a
• /
• pp.153.2-153
• /
• 1996

No Abstract, See Full Text

• Clinical and Experimental Reproductive Medicine
• /
• v.10 no.2
• /
• pp.25-37
• /
• 1983

As the cytogenetic developed, cytogenetic study has also developed progressively. This study is a systematical cytogenetic and clinico-hormonal analysis of 20 cases Wp.ere gonadal dysgenesis was diagnosed and deferred to the Dept. of obstetrics and Gynecology, Yonsei University, Medical School from Jan. 1974 to Aug. 1983. Twenty patients with the diagnosis of gonada dysgenesis have been assesed as to possible correlations between clinical, homonal and cytogenic findings. The desults were as follows; l. Gonadal dysgenesis were found in 20 cases, consisting of 15 cases (75%) of turnurs syndrome, 4 case of pure gonadal dysgenesis (20%), 46. XX and 1 case of mixed gonadal dysgenesis, 45,XO/46,XY. 2. Patients with XO karyotype, turner's ryndorme, have a resonably constant clinical picture of sexual infantilism with streak gonads, short status and webbed neck. 3. 17 cases were found primary amenorhea and two cases were noted with 2 ndary amenorrhea. one case has been presented with menstruation. 4. The rudimentary streak gonads were found in 7 cases of 8 cases and one case has a rudimentary streak gonad on one side and a testis on the contralateral side. 5. The study showed that potients with gonadal dysgenesis had an average of about 4-8 times higher basal FSH and about 3-7 times higher basal LH than that of the early follicular phase of normal menstrual cycle. 6. Two cases of three gonadal dysgenesis patieats, who performed LH-RH challage test, showed that the serum FSH levels reached the maximal level at 30 min after injection of CHRH and the serum LH level reached the maximal level at 60 min ofter injection of LHRH one case showed no significant response to LH-RH injection. Thus, bu studying simultoneously the clinical, cytogenic, hormonal aspects and visualization of gonads, we have gained some practical insight into the requirements for proper disgnosis and treatment.

• Development and Reproduction
• /
• v.11 no.1
• /
• pp.21-29
• /
• 2007

Previously, we found progesterone receptor membrane component 2 (pgrmc2) was highly expressed in germinal vesicle (GV) stage oocytes. The present study was conducted to characterize the expression of pgrmc2, as well as pgrmc1, in the mouse gonads and embryos according to their developmental stages. We found that these membrane components were expressed in ovaries, testes, and embryos at various developmental stages in addition to oocytes. Progesterone-3-O-carboxymethyl oxime-BSA-fluorescein isothiocyanate (P4-BSA-FITC) was applied to visualize the presence of the progesterone receptor on mouse oocyte membrane, and we confirmed that immobilized progesterone is localized at surface of the oocyte. This is, at our knowledge, the first report regarding the expression of membrane component of progesterone receptor in the mouse oocytes, embryos, and gonads. The function and signal transduction pathway of progesterone receptor membrane components in oocytes requires further studies.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.9
• /
• pp.1227-1231
• /
• 2002

A powerful tool for chicken transgenesis could be established by employing a germline chimera production through primordial germ cell transplantation. This study was conducted to examine whether foreign gene-transfected gonadal primordial germ cells (gPGCs) have a migration activity into the gonad after transfer to recipient embryos. In Experiment 1, gPGCs of Korean Ogol Chicken were retrieved from 5.5-day-old embryos and subsequently transferred to the dorsal aorta of 2.5-day-old White Leghorn embryos after being labeled with PKH26 fluorescent dye. To confirm migration activity after transplantation, recipient embryos were sacrificed and examined on 3 days after transfer. Sex determination was concomitantly undertaken to examine whether sex of recipient embryos could affect the migration activity of gPGCs. All of embryonic gonads examined showed positive signals with PKH26 fluorescence and W-chromosome specific band by polymerase chain reaction (PCR) was detected in male embryos when gPGCs with ZW chromosome were transferred to recipient embryos. In Experiment 2, retrieved gPGCs were transfected with LacZ gene-containing cytomegalovirus promoter ($pCMV{\beta}$) by electroporation and subsequently transferred to recipient embryos. LacZ gene expression was identified in the gonads of 6 or 10-day-old recipient embryos and hatched-chicks. A total of 20 embryos and 12 hatched-chicks were examined and 11 of them (10 embryos and one hatched chicken; 11/32=34.4%) expressed $\beta$-galactosidase, a marker substance of LacZ gene. The results of this study demonstrated that foreign gene-transfected gPGCs can migrate and settle down into the gonad after being transferred into the blood vessel of the recipient embryos. This established technique will contribute to developing a peer biotechnology for transgenic chicken.